1. Field of the Invention
This invention relates to the field of transporting articles, particularly articles of a fragile nature. More particularly, this invention relates to the field of automatic handling and moving articles between predetermined stations to and from an intermediate treatment station at which manufacturing procedures are effected on the articles in sequence.
Still more particularly, this invention relates to the field of handling and transporting fragile flat plate-like articles, such as glass or ceramic substrates commonly utilized in the electronics industry in the manufacture of semi-conductor devices, and for treating such substrates during manufacturing procedures. Herein such substrates are referred to as "masks". Such masks are generally in the form of a flat plate having a square or rectangular configuration formed, as noted, from glass, a suitable ceramic, or other suitable material commonly employed in the manufacturing of semi-conductor devices.
Still more particularly, this invention relates to the field of mask transportation means and handling methods which utilize a fluid bearing track adjacent each of an indexable infeed and discharge mask carrier or magazine, coupled with cooperable vacuum transfer arms for accepting masks from the outfeed magazine, and for transferring the same to and precisely locating the masks on a rotatable intermediate vacuum chuck.
While the specific aspects of the handling apparatus and method disclosed herein are related to the handling and treatment of fragile masks, it should be understood that the novel handling and transporting aspects of this invention are utilizible in conjunction with the handling of various other square or rectangular plate-like articles, particularly those of a fragile nature, where precise positioning of such articles relative to a predetermined station is required.
2. Description of the Prior Art
Fluid bearing track structures for transporting articles of various types have been known heretofore. Representative of prior art in which substrate handling apparatus and methods utilizing fluid bearings with indexable outfeed and discharge conveyors are the patents to Lasch, Jr. et al. U.S. Pat. No. 3,645,581 dated Feb. 29, 1972, and Lasch, Jr. U.S. Pat. No. 3,718,371, dated Feb. 27, 1973. Other patents illustrating fluid bearing track structures of various types also have been known heretofore as cited in such noted patents.
The present invention, however, is not directed to known details of construction of indexable magazines for masks or to fluid bearing track structures which may be associated therewith. As pointed out hereinafter and in the appended claims, the present invention is directed to the precise positioning of rectangular or square mask plates to facilitate transfer thereof onto a rotatable vacuum chuck for treatment thereon.
While indexable magazines and fluid bearing track structures have been disclosed in the noted patents and others heretofore, none of such patents or other prior art known to applicant discloses or describes the improved combination of structural features and handling method steps described herein. Therefore, so far as is known, the apparatus and method of this invention have not been known heretofore, particularly in conjunction with the transportation of fragile substrates, such as glass or ceramic masks utilized in the production of semi-conductor devices.